Winter Hot Tub Running

Hey All,

I'm new to the forums and new to spa ownership. I recently bought a house that came with an in-deck hot tub, attached to a pump system located in the garage. The pump connects to an intermatic timer, and we had it inspected upon acceptance of our offer, and everything checked out great. The Ozonater needs to be replaced, but I'll worry about that a little later.

I live in Woodinville, WA (suburb of Seattle, WA) and the winter is right around the corner. Today we experienced our first low 30s temps, as well as our first frost. To be safe, I ran the pump/heater all evening last night. I'm more wondering what a good schedule would be for running the pumps? Our temps here usually only fall under freezing during the evenings, accept for a few low weeks in Jan/Feb.

I plan to drain/clean the tub this weekend, go through a startup process left by the previous owner and then will be using the tub regularly. I was thinking that running it from about 4pm -10pm would be nice so the tub is ready for using, and then would I need to run it any other times? Maybe later in the evening?

Thank you in advance!


TFP Expert
Feb 3, 2014
Central Minnesota
You would obviously need to run it any time you want to raise the temperature. You'd also want to run it when necessary to avoid freezing temperatures in your lines such as when it's going to be near freezing overnight or during the day. You'll likely need to establish heater times AND pump times as you'll likely want the tub to circulate for at least 2 hours per day even when not in use. You'll want to heat whenever necessary...

Some more detail on the set up, length of plumbing lines and whether or not you have separate timing abilities for the pump and heater would help. Feel free to add these details to your forum signature so that others can help and see what you're talking about more readily in each post you make.

Welcome to TFP! :wave:


LifeTime Supporter
Oct 11, 2014
Seattle, WA
I'm just down the road a bit from you - my hot tub has been out on my deck for 14 years and I've never had a problem with it freezing even during week-long plus power failures. It is self contained with a standard hard foam vinyl enclosed cover. I now run it at 88F now and crank it up to 98F 1-2 hrs before I intend to use it, then turn it down again when I get out. I have a circulating pump that runs 24/7 (likely overkill), and the filter cycles are set to run 30 min every 6 hrs. Came from the store that way and I've never changed it. Temp dropped overnight to 28, but my water only dropped 1 degree from the 98F when I used it, even though I had dropped the temp stat to 88F.


LifeTime Supporter
Oct 11, 2014
Seattle, WA
Oh, in addition - as stated by others here, I strongly agree that you should get an outdoor thermometer to see what your micro-environment really is - I'm less than 3 miles from the Bryant weather station on wunderground, but my low temps consistently run 4-6 degrees higher. During the sunny afternoons, I'm a full 20+ degrees warmer on the deck next to the spa - in a sunny wind-blocked area on the south side of the house. That makes a huge difference. The dog bowls do freeze over outside elsewhere in the yard, but not solid through, just the surface.
Thanks for all the replys!

I have settled on running the circulating pump for 1 hour 4x times throughout the evening. I'm keeping out temp at 90F, and then turn it up when it's time to go in. It does heat pretty quickly.

My spa and system are very old, there is no real way to just run certain pumps. It connects to an intermatic timer and that is where I have it running the 4 1 hour cycles (4 hours total).

good call with getting a temp gauge, will do immediately.


LifeTime Supporter
Jul 3, 2014
Peoria, IL
I would not replace the ozone generator. I had one on our tub when we inherited it. It was 8 years old and likely not functioning. I removed and went with Nature2 for the spa. My pool is separate and SWG.

We have done chlorine, bromine and everything in between for hot tubs in the past. Nature2 is by far the easiest.
I balance the ph and at and or the next 4 months do nothing but shock the tub when we are done using or at least weekly.

We keep ours set at about 95 and bump to 100 right before we get in. In summer we drop the temp, but for winter we like it warmer.

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